Question

one student group hypothesized that the dry baker's yeast must be alive. the temperature change, odor, and bubble formation, they said, indicated which characteristic of life.

Answer 1

A) be made of one or more cells

B) detect and respond to select external stimuli

C) have some form of nucleic acid as the hereditary molecule

D) show growth and development; that is, specialization of cells or structures

Answer 2

The changing temperature, odor and bubble formation all indicate that the yeast is responding to external stimuli. This is a characteristic of living organisms. They will respond to changes in their environment. The changes that occur here are a result of the yeast using the sugars in the dough to carry out respiration.